Is rust-proofing worth the cost?

By Romana King on January 11, 2011
Estimated reading time: 2 minutes

Not in California, perhaps. But here in Canada, where your car will be assaulted by gravel, ice and salt? You bet.

Rust. It’s a four-letter word that can wreak havoc on a car—and your wallet. So wouldn’t it make sense to pay for some extra protection?

If you lived in California, like Dan Edmunds, director of vehicle testing at Edmunds.com, he’d tell you after-market rust protection is a waste of time. But you don’t. You live in Canada, where ice, snow, salt and dramatic climate fluctuations, combined with thousands of kilometres of gravel roads, can chip away your car’s built-in protection in no time. Because of that, Edmunds believes that even drivers in temperate areas of Canada would benefit from rust protection.

Much of the damage to your car’s existing rust coating is caused by driving on unpaved roadways, like those found in cottage country or at national parks and campgrounds across Canada. “The stones fly up and grind and chip and work at the surfaces on the undercarriage of the car,” explains Edmunds. “This particular kind of damage—repetitive surface damage—can leave exposed areas that become susceptible to corrosion.”

If you update your ride every couple of years, getting a spray-on rust coating isn’t worth it. But if you plan on driving your car into the ground, it can lengthen your car’s life. “The additional protection and cost only makes sense if you plan on keeping your car over the long term,” says Edmunds.

After-market protection costs roughly $150 for 12 to 18 months of protection, says Kirk Robinson, owner of Robinson Automotive in Mississauga, Ont. He says rust-proofing can prevent a variety of repairs, such as fuel line corrosion—which can cost $1,000 to fix.

So which type of rust-proofing should you go for? That’s easy, says Robinson. “About two years ago the Canadian army tested every rust-proofing brand on the market.” The top pick was Corrosion FREE’s Formula 3000, with an 83% success rate. Other brands rated as low as 28%.

Robinson’s final advice? Wash your car’s undercarriage before taking it in, and stay away from sprays that are thick or waxy. “Those promote air pockets,” he says, “and that’s where you get rust.”